diff --git a/src/bfu/hierbox.c b/src/bfu/hierbox.c
index 399ff4d7..5b844bc0 100644
--- a/src/bfu/hierbox.c
+++ b/src/bfu/hierbox.c
@@ -43,7 +43,7 @@ add_listbox_item(struct hierbox_browser *browser, struct listbox_item *root,
 	struct listbox_item *item;
 
 	if (!root) {
-		assertm(browser, "Nowhere to add new list box item");
+		assertm(browser != NULL, "Nowhere to add new list box item");
 		root = &browser->root;
 	}
 
diff --git a/src/bfu/menu.c b/src/bfu/menu.c
index 0a1da0e4..4511a569 100644
--- a/src/bfu/menu.c
+++ b/src/bfu/menu.c
@@ -171,7 +171,7 @@ select_menu_item(struct terminal *term, struct menu_item *it, void *data)
 		return;
 	}
 
-	assertm(func, "No menu function");
+	assertm(func != NULL, "No menu function");
 	if_assert_failed return;
 
 	func(term, it_data, data);
diff --git a/src/bookmarks/dialogs.c b/src/bookmarks/dialogs.c
index bb6fa448..e247f943 100644
--- a/src/bookmarks/dialogs.c
+++ b/src/bookmarks/dialogs.c
@@ -602,7 +602,7 @@ bookmark_search_do(void *data)
 	struct listbox_data *box;
 	struct dialog_data *dlg_data;
 
-	assertm(dlg->udata, "Bookmark search with NULL udata in dialog");
+	assertm(dlg->udata != NULL, "Bookmark search with NULL udata in dialog");
 	if_assert_failed return;
 
 	ctx.title = dlg->widgets[0].data;
diff --git a/src/config/options.c b/src/config/options.c
index 7c20e11f..43d22446 100644
--- a/src/config/options.c
+++ b/src/config/options.c
@@ -197,7 +197,7 @@ get_opt_rec(struct option *tree, const unsigned char *name_)
 	if (tree && tree->flags & OPT_AUTOCREATE && !no_autocreate) {
 		struct option *template = get_opt_rec(tree, "_template_");
 
-		assertm(template, "Requested %s should be autocreated but "
+		assertm(template != NULL, "Requested %s should be autocreated but "
 			"%.*s._template_ is missing!", name_, sep - name_,
 			name_);
 		if_assert_failed {
@@ -391,7 +391,7 @@ add_opt_rec(struct option *tree, unsigned char *path, struct option *option)
 	assert(path && option && tree);
 	if (*path) tree = get_opt_rec(tree, path);
 
-	assertm(tree, "Missing option tree for '%s'", path);
+	assertm(tree != NULL, "Missing option tree for '%s'", path);
 	if (!tree->value.tree) return;
 
 	object_nolock(option, "option");
diff --git a/src/config/opttypes.c b/src/config/opttypes.c
index db8b7b7d..8ef3ea05 100644
--- a/src/config/opttypes.c
+++ b/src/config/opttypes.c
@@ -94,7 +94,7 @@ exec_cmd(struct option *o, unsigned char ***argv, int *argc)
 { \
 	struct option *real = get_opt_rec(config_options, opt->value.string); \
  \
-	assertm(real, "%s aliased to unknown option %s!", opt->name, opt->value.string); \
+	assertm(real != NULL, "%s aliased to unknown option %s!", opt->name, opt->value.string); \
 	if_assert_failed { return ret_; } \
  \
 	if (option_types[real->type].name_) \
@@ -109,7 +109,7 @@ redir_cmd(struct option *opt, unsigned char ***argv, int *argc)
 	struct option *real = get_opt_rec(config_options, opt->value.string);
 	unsigned char * ret = NULL;
 
-	assertm(real, "%s aliased to unknown option %s!", opt->name, opt->value.string);
+	assertm(real != NULL, "%s aliased to unknown option %s!", opt->name, opt->value.string);
 	if_assert_failed { return ret; }
 
 	if (option_types[real->type].cmdline) {
@@ -131,7 +131,7 @@ redir_wr(struct option *opt, struct string *string)
 {
 	struct option *real = get_opt_rec(config_options, opt->value.string);
 
-	assertm(real, "%s aliased to unknown option %s!", opt->name, opt->value.string);
+	assertm(real != NULL, "%s aliased to unknown option %s!", opt->name, opt->value.string);
 	if_assert_failed { return; }
 
 	if (option_types[real->type].write)
@@ -144,7 +144,7 @@ redir_set(struct option *opt, unsigned char *str)
 	struct option *real = get_opt_rec(config_options, opt->value.string);
 	int ret = 0;
 
-	assertm(real, "%s aliased to unknown option %s!", opt->name, opt->value.string);
+	assertm(real != NULL, "%s aliased to unknown option %s!", opt->name, opt->value.string);
 	if_assert_failed { return ret; }
 
 	if (option_types[real->type].set) {
diff --git a/src/document/html/tables.c b/src/document/html/tables.c
index c5b9a3df..26515530 100644
--- a/src/document/html/tables.c
+++ b/src/document/html/tables.c
@@ -196,7 +196,7 @@ again:
 	}
 
 	if (wanted) {
-		assertm(limits, "bug in distribute_values()");
+		assertm(limits != NULL, "bug in distribute_values()");
 		limits = NULL;
 		sum = 0;
 		goto again;
diff --git a/src/dom/node.c b/src/dom/node.c
index 6f97cfb6..f77a8d78 100644
--- a/src/dom/node.c
+++ b/src/dom/node.c
@@ -371,7 +371,7 @@ init_dom_node_at(
 		int sort = (type == DOM_NODE_ATTRIBUTE);
 		int index;
 
-		assertm(list, "Adding node %d to bad parent %d",
+		assertm(list != NULL, "Adding node %d to bad parent %d",
 			node->type, parent->type);
 
 		index = *list && (*list)->size > 0 && sort
diff --git a/src/dom/select.c b/src/dom/select.c
index 472bd07f..b7b7e599 100644
--- a/src/dom/select.c
+++ b/src/dom/select.c
@@ -488,7 +488,7 @@ parse_dom_select(struct dom_select *select, struct dom_stack *stack,
 			int sort = (node->type == DOM_NODE_ATTRIBUTE);
 			int index;
 
-			assertm(list, "Adding node to bad parent [%d -> %d]",
+			assertm(list != NULL, "Adding node to bad parent [%d -> %d]",
 				node->type, parent->type);
 
 			index = *list && (*list)->size > 0 && sort
diff --git a/src/dom/stack.h b/src/dom/stack.h
index 2e5b24c9..820bbb46 100644
--- a/src/dom/stack.h
+++ b/src/dom/stack.h
@@ -189,7 +189,7 @@ get_dom_stack_state_data(struct dom_stack_context *context,
 
 	if (!object_size) return NULL;
 
-	assertm(context->state_objects);
+	assert(context->state_objects);
 
 	return (void *) &context->state_objects[state->depth * object_size];
 }
diff --git a/src/ecmascript/ecmascript.c b/src/ecmascript/ecmascript.c
index c7cd24b4..bd7d2083 100644
--- a/src/ecmascript/ecmascript.c
+++ b/src/ecmascript/ecmascript.c
@@ -311,7 +311,9 @@ ecmascript_timeout_handler(void *i)
 {
 	struct ecmascript_interpreter *interpreter = i;
 
-	assertm(interpreter->vs->doc_view, "setTimeout: vs with no document (e_f %d)", interpreter->vs->ecmascript_fragile);
+	assertm(interpreter->vs->doc_view != NULL,
+		"setTimeout: vs with no document (e_f %d)",
+		interpreter->vs->ecmascript_fragile);
 	interpreter->vs->doc_view->document->timeout = TIMER_ID_UNDEF;
 	/* The expired timer ID has now been erased.  */
 
diff --git a/src/main/event.c b/src/main/event.c
index 9153ca0e..91e1c0c9 100644
--- a/src/main/event.c
+++ b/src/main/event.c
@@ -132,7 +132,7 @@ get_event_id(unsigned char *name)
 	if (item) {
 		struct event *event = item->value;
 
-		assertm(event, "Hash item with no value");
+		assertm(event != NULL, "Hash item with no value");
 		if_assert_failed return EVENT_NONE;
 
 		return event->id;
diff --git a/src/network/connection.c b/src/network/connection.c
index 8ab89ac8..1cfc7e95 100644
--- a/src/network/connection.c
+++ b/src/network/connection.c
@@ -1015,7 +1015,7 @@ cancel_download(struct download *download, int interrupt)
 	if (is_in_result_state(download->state))
 		return;
 
-	assertm(download->conn, "last state is %d", download->state);
+	assertm(download->conn != NULL, "last state is %d", download->state);
 
 	check_queue_bugs();
 
@@ -1074,7 +1074,7 @@ move_download(struct download *old, struct download *new,
 		return;
 	}
 
-	assertm(old->conn, "last state is %d", old->state);
+	assertm(old->conn != NULL, "last state is %d", old->state);
 
 	conn->pri[new->pri]++;
 	add_to_list(conn->downloads, new);
diff --git a/src/network/socket.c b/src/network/socket.c
index 732f782e..d39f874c 100644
--- a/src/network/socket.c
+++ b/src/network/socket.c
@@ -455,7 +455,7 @@ connected(struct socket *socket)
 	int err = 0;
 	socklen_t len = sizeof(err);
 
-	assertm(socket->connect_info, "Lost connect_info!");
+	assertm(socket->connect_info != NULL, "Lost connect_info!");
 	if_assert_failed return;
 
 	if (getsockopt(socket->fd, SOL_SOCKET, SO_ERROR, (void *) &err, &len) == 0) {
@@ -672,7 +672,7 @@ write_select(struct socket *socket)
 	struct write_buffer *wb = socket->write_buffer;
 	int wr;
 
-	assertm(wb, "write socket has no buffer");
+	assertm(wb != NULL, "write socket has no buffer");
 	if_assert_failed {
 		socket->ops->done(socket, S_INTERNAL);
 		return;
@@ -802,7 +802,7 @@ read_select(struct socket *socket)
 	struct read_buffer *rb = socket->read_buffer;
 	ssize_t rd;
 
-	assertm(rb, "read socket has no buffer");
+	assertm(rb != NULL, "read socket has no buffer");
 	if_assert_failed {
 		socket->ops->done(socket, S_INTERNAL);
 		return;
diff --git a/src/protocol/bittorrent/piececache.c b/src/protocol/bittorrent/piececache.c
index b6ef4a6e..80b54d99 100644
--- a/src/protocol/bittorrent/piececache.c
+++ b/src/protocol/bittorrent/piececache.c
@@ -379,7 +379,7 @@ add_piece_to_bittorrent_free_list(struct bittorrent_piece_cache *cache,
 		return NULL;
 	}
 
-	assertm(piece_offset == piece_length);
+	assert(piece_offset == piece_length);
 	assertm(blocks, "Piece was not divided into blocks");
 	assert(!cache->entries[piece].blocks);
 
@@ -1221,7 +1221,7 @@ update_bittorrent_piece_cache_state(struct bittorrent_connection *bittorrent)
 	foreachsafe (entry, next, cache->queue) {
 		uint32_t piece_length, piece;
 
-		assertm(entry->data && entry->completed);
+		assert(entry->data && entry->completed);
 
 		piece = entry - cache->entries;
 
diff --git a/src/protocol/uri.c b/src/protocol/uri.c
index ba86d64f..634688b5 100644
--- a/src/protocol/uri.c
+++ b/src/protocol/uri.c
@@ -194,7 +194,7 @@ parse_uri(struct uri *uri, unsigned char *uristring)
 	unsigned char *lbracket, *rbracket;
 #endif
 
-	assertm(uristring, "No uri to parse.");
+	assertm(uristring != NULL, "No uri to parse.");
 	memset(uri, 0, sizeof(*uri));
 
 	/* Nothing to do for an empty url. */
@@ -923,7 +923,7 @@ join_urls(struct uri *base, unsigned char *rel)
 		}
 	}
 
-	assertm(base->data, "bad base url");
+	assertm(base->data != NULL, "bad base url");
 	if_assert_failed return NULL;
 
 	path = base->data;
@@ -1201,7 +1201,7 @@ parse_uri:
 			   ? uri.port + uri.portlen - struri(&uri)
 			   : uri.host + uri.hostlen - struri(&uri) + uri.ipv6 /* ']' */;
 
-		assertm(uri.host, "uri.host not set after no host slash error");
+		assertm(uri.host != NULL, "uri.host not set after no host slash error");
 		insert_in_string(&newurl, offset, "/", 1);
 		goto parse_uri;
 	}
@@ -1596,7 +1596,7 @@ done_uri(struct uri *uri)
 	item = get_hash_item(uri_cache.map, string, length);
 	entry = item ? item->value : NULL;
 
-	assertm(entry, "Releasing unknown URI [%s]", string);
+	assertm(entry != NULL, "Releasing unknown URI [%s]", string);
 	del_hash_item(uri_cache.map, item);
 	mem_free(entry);
 
diff --git a/src/session/task.c b/src/session/task.c
index 27e2f55c..8d87462b 100644
--- a/src/session/task.c
+++ b/src/session/task.c
@@ -463,7 +463,7 @@ do_move(struct session *ses, struct download **download_p)
 	struct cache_entry *cached;
 
 	assert(download_p && *download_p);
-	assertm(ses->loading_uri, "no ses->loading_uri");
+	assertm(ses->loading_uri != NULL, "no ses->loading_uri");
 	if_assert_failed return DO_MOVE_ABORT;
 
 	if (ses->loading_uri->protocol == PROTOCOL_UNKNOWN)
diff --git a/src/terminal/event.c b/src/terminal/event.c
index 6d5dc40c..237ff5b2 100644
--- a/src/terminal/event.c
+++ b/src/terminal/event.c
@@ -124,7 +124,7 @@ term_send_event(struct terminal *term, struct term_event *ev)
 		win = term->windows.next;
 		if (win->type == WINDOW_TAB) {
 			win = get_current_tab(term);
-			assertm(win, "No tab to send the event to!");
+			assertm(win != NULL, "No tab to send the event to!");
 			if_assert_failed return;
 		}
 
diff --git a/src/util/fastfind.c b/src/util/fastfind.c
index 004701d6..3ee3bb5f 100644
--- a/src/util/fastfind.c
+++ b/src/util/fastfind.c
@@ -596,7 +596,7 @@ fastfind_search(struct fastfind_index *index, unsigned char *key, int key_len)
 
 	info = index->handle;
 
-	assertm(info, "FastFind index %s not initialized", index->comment);
+	assertm(info != NULL, "FastFind index %s not initialized", index->comment);
 	if_assert_failed return NULL;
 
 	FF_DBG_search_stats(info, key_len);
diff --git a/src/util/memlist.c b/src/util/memlist.c
index ed24ccd7..f3397532 100644
--- a/src/util/memlist.c
+++ b/src/util/memlist.c
@@ -26,7 +26,7 @@
 /* Create a memory list. If p is NULL or allocation fails, it will
  * returns NULL.
  * It always stops at first NULL element. */
-#ifdef DEBUG_MEMLIST
+#if defined(DEBUG_MEMLIST) && defined(HAVE_VARIADIC_MACROS)
 struct memory_list *
 debug_getml(unsigned char *file, int line, void *p, ...)
 #else
@@ -69,7 +69,7 @@ getml(void *p, ...)
  * If memory list exists, it enlarges it, else it creates it.
  * if there's no elements or first element is NULL, it does nothing.
  * It always stops at first NULL element. */
-#ifdef DEBUG_MEMLIST
+#if defined(DEBUG_MEMLIST) && defined(HAVE_VARIADIC_MACROS)
 void
 debug_add_to_ml(unsigned char *file, int line, struct memory_list **ml, ...)
 #else
@@ -89,7 +89,11 @@ add_to_ml(struct memory_list **ml, ...)
 	/* None, so just return. */
 	if (!n) {
 #ifdef DEBUG_MEMLIST
+#ifdef HAVE_VARIADIC_MACROS
 		errline = line, errfile = file;
+#else
+		errline = 0, errfile = "?";
+#endif 
 		elinks_error("add_to_ml(%p, NULL, ...)", ml);
 #endif
 		return;
diff --git a/src/util/string.c b/src/util/string.c
index 6d70faa4..d95ca18b 100644
--- a/src/util/string.c
+++ b/src/util/string.c
@@ -139,7 +139,7 @@ straconcat(const unsigned char *str, ...)
 	unsigned char *s;
 	unsigned int len;
 
-	assertm(str, "[straconcat]");
+	assertm(str != NULL, "[straconcat]");
 	if_assert_failed { return NULL; }
 
 	len = strlen(str);
@@ -250,7 +250,7 @@ init_string__(const unsigned char *file, int line, struct string *string)
 init_string(struct string *string)
 #endif
 {
-	assertm(string, "[init_string]");
+	assertm(string != NULL, "[init_string]");
 	if_assert_failed { return NULL; }
 
 	string->length = 0;
@@ -271,7 +271,7 @@ init_string(struct string *string)
 inline void
 done_string(struct string *string)
 {
-	assertm(string, "[done_string]");
+	assertm(string != NULL, "[done_string]");
 	if_assert_failed { return; }
 
 	if (string->source) {
@@ -302,7 +302,7 @@ add_to_string(struct string *string, const unsigned char *source)
 inline struct string *
 add_crlf_to_string(struct string *string)
 {
-	assertm(string, "[add_crlf_to_string]");
+	assertm(string != NULL, "[add_crlf_to_string]");
 	if_assert_failed { return NULL; }
 
 	check_string_magic(string);
@@ -377,7 +377,7 @@ string_concat(struct string *string, ...)
 	va_list ap;
 	const unsigned char *source;
 
-	assertm(string, "[string_concat]");
+	assertm(string != NULL, "[string_concat]");
 	if_assert_failed { return NULL; }
 
 	check_string_magic(string);
@@ -496,7 +496,7 @@ add_to_string_list(struct list_head *list, const unsigned char *source,
 void
 free_string_list(struct list_head *list)
 {
-	assertm(list, "[free_string_list]");
+	assertm(list != NULL, "[free_string_list]");
 	if_assert_failed return;
 
 	while (!list_empty(*list)) {
diff --git a/src/viewer/text/form.c b/src/viewer/text/form.c
index f37673ce..595d046d 100644
--- a/src/viewer/text/form.c
+++ b/src/viewer/text/form.c
@@ -322,7 +322,7 @@ draw_form_entry(struct terminal *term, struct document_view *doc_view,
 	if_assert_failed return;
 
 	fc = get_link_form_control(link);
-	assertm(fc, "link %d has no form control", (int) (link - doc_view->document->links));
+	assertm(fc != NULL, "link %d has no form control", (int) (link - doc_view->document->links));
 	if_assert_failed return;
 
 	fs = find_form_state(doc_view, fc);
@@ -1366,7 +1366,7 @@ field_op(struct session *ses, struct document_view *doc_view,
 	if_assert_failed return FRAME_EVENT_OK;
 
 	fc = get_link_form_control(link);
-	assertm(fc, "link has no form control");
+	assertm(fc != NULL, "link has no form control");
 	if_assert_failed return FRAME_EVENT_OK;
 
 	if (fc->mode == FORM_MODE_DISABLED || ev->ev != EVENT_KBD
diff --git a/src/viewer/text/search.c b/src/viewer/text/search.c
index f13cb6cf..18c44468 100644
--- a/src/viewer/text/search.c
+++ b/src/viewer/text/search.c
@@ -1372,7 +1372,7 @@ text_typeahead_handler(struct input_line *line, int action_id)
 	int report_errors = action_id == -1;
 	enum find_error error;
 
-	assertm(doc_view, "document not formatted");
+	assertm(doc_view != NULL, "document not formatted");
 	if_assert_failed return INPUT_LINE_CANCEL;
 
 	switch (action_id) {
@@ -1437,7 +1437,7 @@ link_typeahead_handler(struct input_line *line, int action_id)
 	struct document_view *doc_view = current_frame(ses);
 	int offset = 0;
 
-	assertm(doc_view, "document not formatted");
+	assertm(doc_view != NULL, "document not formatted");
 	if_assert_failed return INPUT_LINE_CANCEL;
 
 	/* If there is nothing to match with don't start searching */
diff --git a/src/viewer/text/textarea.c b/src/viewer/text/textarea.c
index 727cb623..76092cc7 100644
--- a/src/viewer/text/textarea.c
+++ b/src/viewer/text/textarea.c
@@ -330,7 +330,7 @@ draw_textarea_utf8(struct terminal *term, struct form_state *fs,
 	assert(term && doc_view && doc_view->document && doc_view->vs && link);
 	if_assert_failed return;
 	fc = get_link_form_control(link);
-	assertm(fc, "link %d has no form control", (int) (link - doc_view->document->links));
+	assertm(fc != NULL, "link %d has no form control", (int) (link - doc_view->document->links));
 	if_assert_failed return;
 
 	box = &doc_view->box;
@@ -419,7 +419,7 @@ draw_textarea(struct terminal *term, struct form_state *fs,
 	}
 #endif /* CONFIG_UTF8 */
 	fc = get_link_form_control(link);
-	assertm(fc, "link %d has no form control", (int) (link - doc_view->document->links));
+	assertm(fc != NULL, "link %d has no form control", (int) (link - doc_view->document->links));
 	if_assert_failed return;
 
 	box = &doc_view->box;
@@ -1206,7 +1206,7 @@ set_textarea(struct document_view *doc_view, int direction)
 		return;
 
 	fc = get_link_form_control(link);
-	assertm(fc, "link has no form control");
+	assertm(fc != NULL, "link has no form control");
 	if_assert_failed return;
 
 	if (fc->mode == FORM_MODE_DISABLED) return;